1. Field of the Disclosed Embodiments
This disclosure relates to systems and methods for implementing unique multi-band service discovery protocols between communicating devices. These communicating devices include wireless communicating devices supporting operations according to multiple standards and in different frequency bands, particularly in peer-to-peer or ad hoc networking schemes.
2. Related Art
The term “service discovery” refers to schemes that enable a first communicating device, often a wireless communicating device, to automatically discover, or “sense,” the services that may be provided, or supported, by one or more second communicating devices with which the first communicating device attempts to establish communication. The first communicating device may, for example, execute one or more service discovery protocols (SDPs). SDPs are generally network communication protocols that provide for automatic detection and identification of (1) other (one or more second) communicating devices with which the communicating device may attempt to establish communication, and (2) the services offered by the other communicating devices operating in established or ad hoc communicating networks. Service discovery is conventionally understood to require a common language that may allow the individual communicating devices to make use of the other device's services without the need for continuous user intervention.
As used in this disclosure, and as is commonly understood to those of skill in the art, the term “service” is intended to refer to a single utility, or a suite of utilities, that have meaning from a point of view of a user of a communicating device. These services may include, for example, computing services, communicating services, printing services, display services, or the like. Different standards may define different services and different service discovery protocols. For example, in the Wi-Fi Alliance (WFA) peer-to-peer (P2P) specification, the following services are specified:                (1) Universal Plug and Play (UPnP), which permits networked devices, such as personal computers, printers, Internet gateways, Wi-Fi access points and mobile devices to seamlessly discover each other's presence on the network and to establish functional network services for data sharing, communication, and entertainment;        (2) Bonjour, which is an Apple proprietary implementation of zero configuration networking according to a set of techniques that automatically create a usable IP network without manual operator intervention or special configuration servers, including implementing service discovery, address assignment and hostname resolution;        (3) Web Services Dynamic Discovery (WS-Discovery), which defines a multicast discovery protocol to locate services on a local network, the communication between nodes being done using web services standards such as, for example, SOAP-over-UDP; and        (4) Wi-Fi Display, which is the new standard for exchange of, for example, three-dimensional videos compressed to travel over Wi-Fi connections between devices. In addition, organizations other than the WFA have also defined services. The Wireless Gigabit (WiGig) Alliance has separately defined the WiGig Display Extension, WiGig Serial Extension, WiGig Bus Extension and WiGig SD Extension standards. Similarly, the Bluetooth Special Interest Group (SIG) has defined its own service standards.        
An implementing and/or operating assumption that is common across all of these exemplary service discovery protocols, as they are currently available, is that a service, once discovered, applies to all of the frequency bands that a particular communicating device supports. This implementing assumption is illustrated in an exemplary manner with the simple communicating system 100 shown in FIG. 1. As shown in FIG. 1, Device A 110 and Device B 150 both support two frequency bands each: Band X 120,160 (e.g., 2.4 GHz) and Band Y 130,170 (e.g., 5 GHz). In the example shown in FIG. 1, Device A 110 sends a Service Discovery Query frame to Device B 150 over Band X 120. In the Service Discovery Response frame that Device A 110 receives from Device B 150, an indication is provided that Device B 150 supports, for example, Wi-Fi Display. If Device A 110 also supports Wi-Fi Display, then both devices, Device A 110 and Device B 150, can proceed to start a Wi-Fi Display session between them.
A difficulty with an implementation such as that illustrated in the example shown in FIG. 1 is that it is based on an implicit assumption, as mentioned above, that the discovered service, in this instance Wi-Fi Display, can operate over both Band X 120,160 and Band Y 130,170. This assumption has generally been considered valid for existing implementations. Today, there is an increasing proliferation of devices that heterogeneously combine operations of multiple radios. The multiple radios support disparate service systems operating according to different standards, and in different frequency ranges. As an example, WiGig systems operating in the unlicensed 60 GHz frequency band may be supported in a same communicating device housing a Wi-Fi system operating in the unlicensed 2.4 and/or 5 GHz frequency band(s). Many variations of communication technologies are being hosted on similarly appearing and seemingly similarly operating devices. The assumption, however, that a discovered service is supportable by one or all of the radios in a particular device is becoming less likely to be valid as specified non-cooperating devices host differing applications and services. In particular, it is becoming generally recognized that the set of services supported by 60 GHz capable radios, for example, will likely not fully coincide with the set of services supported by other band communication radios that may be supported by the same communicating device. In other words, in the example illustration depicted in FIG. 1, and as discussed above, while Wi-Fi Display is a service supported over Band X 120,160, there is no guarantee that the conventional assumption that Wi-Fi Display as a service will also necessarily be supported over Band Y 130,170 in instances where Band Y 130,170 is a 60 GHz frequency band.
In short, some services will likely be unique to only certain bands. This will represent a departure from devices as they are made available today. Generally, conventional multi-radio devices employ the Internet as the default universal translator for supporting different services on different bands. Multi-radio protocols will soon remove the Internet from a particular communication scheme between cooperating devices. Services are being developed that are device centric and that may be exchanged between communicating devices directly. These services will not pass through the Internet or some other intermediary service that may be accessed via some wireless access point, for example. A simple example may involve downloading video files from a wireless handheld communicating device directly to a user's television for display.